Abstract

The characteristics of the sound field of under-expanded cold jet impingement flows were studied by measuring the noise emanating from two convergent and one convergent-divergent nozzle when the jet impinges on a flat plate kept perpendicular to the direction of the jet. The measurements were conducted upstream of the nozzle over an extensive envelope of jet operating conditions such as chamber stagnation pressure, mass flow rate through the nozzle, and diameter of the nozzle.